In recent years, it is desired to widely popularize hybrid vehicles and electric automobiles in a short time in order to reduce the environmental load. In hybrid vehicles and electric automobiles, reduction of the sizes of mounted components and reduction of the cost are regarded as important, and a power conversion apparatus is not the exception and the size and the cost of the power conversion apparatus are desired to be reduced. As a result, since the density of heat generation becomes high, it is necessary to improve the cooling performance.
Among electronic components constituting the power conversion apparatus, the highest amount of heat generation is made by a power module. A known example of method for cooling the power module is a both-sides direct cooling method for inserting a power module into a cooling channel and cooling the power module by way of radiation fins provided at both sides (see PTL 1).
The power module described in PTL 1 is made by sandwiching a semiconductor chip with conductive plates and performing vacuum thermocompression bonding upon interposing insulating sheets between the conductive plates and first and second heat sinks, and adhering a bottom case, a top case, and a side case to the integrally structured heat sinks with an adhesive.